Conventionally, apparatuses which encode a moving image signal and a sound signal and records them on a magnetic tape or plays back them.
Particularly, of apparatuses of this type, VTRs which record or play back a moving image signal and a sound signal in accordance with an encoding scheme called DV format are known as consumer appliances. In the DV format, a moving image signal is encoded in a frame, and a sound signal corresponding to the moving image signal is encoded by PCM (Pulse Code Modulation) and recorded on a recording medium. The video signal and sound signal, which are encoded by the DV format are synchronized. Hence, when signals recorded on a magnetic tape by continuous recording are played back, the continuity of moving images and sound is maintained.
In recent years, VTRs which record a moving image signal and a sound signal on a magnetic tape by MPEG (Moving Picture Experts Group) have also made their debuts. Even for such VTRs using MPEG, methods which allow seamless playback in continuous recording have been proposed and disclosed in, e.g., Japanese Patent Laid-Open No. 10-262211.
In recording a video signal and a sound signal compressed by MPEG on a recording medium, the video signal is encoded for each GOP (Group Of Pictures) including a predetermined number of frames including intra-frame encoded images of one frame. However, the sound signal is encoded for an arbitrary number of samples.
For this reason, the encoding unit of moving image signals does not coincide with that of sound signals. Hence, as shown in FIG. 8, when recording of moving image signals is stopped, a sound signal of a frame for which encoding is not ended yet is not recorded. In playback, sound signals at the continuous recording portion cannot keep the continuity so that a silent portion is generated. This may make seamless playback impossible.
When recording is done by MPEG, as shown in FIG. 9, decoding of the start frame after continuous recording may be delayed due to a factor such as the VBV (Video Buffering Verifier) buffer control amount or GOP structure, and the image of the frame before the continuous recording may be played back in a freeze state. At this time, sound of the frame after the continuous recording is decoded and played back so that the moving image signal and sound signal, which are played back, do not match.